Friedman et al. (1995) reported that 2% of the residents of Bengkala, an Indonesian village on the north shore of Bali, have profound, congenital, neurosensory, nonsyndromal deafness due to an autosomal recessive mutation at a locus designated DFNB3 ... Friedman et al. (1995) reported that 2% of the residents of Bengkala, an Indonesian village on the north shore of Bali, have profound, congenital, neurosensory, nonsyndromal deafness due to an autosomal recessive mutation at a locus designated DFNB3 (for the third autosomal recessive, nonsyndromic deafness locus to be mapped). This remote village dates to at least the 13th century as documented by charters inscribed in Sanskrit on metallic plates. Of the 2,185 residents, 47 had profound deafness of the type described. As an adaptation to the high percentage of deaf individuals, the citizens of Bengkala had developed a unique sign language used by most of the hearing persons as well as the deaf villagers. Deaf couples produced all deaf progeny. In 4- and 5-generation Bengkala kindreds, 2 of which were illustrated, there were no consanguineous marriages. The deaf individuals had no apparent vestibular abnormalities or dysmorphic features.
In a large multigenerational consanguineous Brazilian pedigree with prelingual severe to profound sensorineural deafness, negative for mutations in the deafness-associated GJB2 (121011) and GJB6 (604418) genes and for the A1555G mitochondrial mutation in the MTRNR1 gene (561000.0001), Lezirovitz ... In a large multigenerational consanguineous Brazilian pedigree with prelingual severe to profound sensorineural deafness, negative for mutations in the deafness-associated GJB2 (121011) and GJB6 (604418) genes and for the A1555G mitochondrial mutation in the MTRNR1 gene (561000.0001), Lezirovitz et al. (2008) identified unexpected genetic heterogeneity: 15 affected individuals from 'branch 2' of the family were homozygous for a 1-bp deletion (10573delA; 602666.0012) in the MYO15A gene, whereas 4 affected sibs from 'branch 1' and 1 individual from 'branch 2' were compound heterozygous for 10573delA and a 4-bp deletion (602666.0013) in MYO15A. In 1 patient, only the 10573delA mutation could be identified. No mutations in MYO15A were identified in 5 patients from 2 additional branches of the family: the 3 mutation-negative patients from 'branch 4' of the family had a distinct clinical presentation, with 2 having mental retardation and 1 a mixed hearing loss, whereas the 2 mutation-negative patients from 'branch 3' had a phenotype similar to that of their mutation-positive relatives.
Winata et al. (1995) studied further the congenital deafness prevalent in the Bengkala village population. They estimated the frequency of the DFNB3 mutant allele to be 9.4% among hearing people, who have a 17.2% chance of being heterozygotes. ... Winata et al. (1995) studied further the congenital deafness prevalent in the Bengkala village population. They estimated the frequency of the DFNB3 mutant allele to be 9.4% among hearing people, who have a 17.2% chance of being heterozygotes.